Search results for "HIGGS"
showing 10 items of 1127 documents
Higgs Sector of the Minimal Left-Right Symmetric Model
2001
We perform an exhaustive analysis of the most general Higgs sector of the minimal left-right symmetric model (MLRM). We find that the CP properties of the vacuum state are connected to the Higgs spectrum: if CP is broken spontaneously, the MLRM does not approach the Standard Model in the limit of a decoupling left-right symmetry breaking scale. Depending on the size of the CP phases scenarios with extra non-decoupling flavor-violating doublet Higgses or very light SU(2) triplet Higgses emerge, both of which are ruled out by phenomenology. For zero CP phases the non-standard Higgses decouple only if a very unnatural fine-tuning condition is fulfilled. We also discuss generalizations to a non…
Electroweak baryogenesis window in non standard cosmologies
2012
In this work we show that the new bounds on the Higgs mass are more than difficult to reconcile with the strong constraints on the physical parameters of the Standard Model and the Minimal Supersymmetric Standard Model imposed by the preservation of the baryon asymmetry. This bound can be weakened by assuming a nonstandard cosmology at the time of the electroweak phase transition, reverting back to standard cosmology by BBN time. Two explicit examples are an early period of matter dominated expansion due to a heavy right handed neutrino (see-saw scale), or a nonstandard braneworld expansion.
Flavor changing neutral currents in the dualized standard model
1998
The Dualized Standard Model which gives explanations for both fermion generations and Higgs fields has already been used to calculate fermion mass and mixing parameters with success. In this paper, we extend its application to low energy FCNC effects deriving bounds for various processes in terms of one single mass scale. Using then experimental information from K_L - K_S mass difference and air showers beyond the GZK cut-off, these bounds are converted into rough, order-of-magnitude predictions. In particular, the estimates for the decay K_L \to e^\pm \mu^\mp and for the mass difference between the neutral D-mesons seem accessible to experiment in the near future.
Unnatural origin of fermion masses for technicolor
2009
We explore the scenario in which the breaking of the electroweak symmetry is due to the simultaneous presence and interplay of a dynamical sector and an unnatural elementary Higgs. We introduce a low energy effective Lagrangian and constrain the various couplings via direct search limits and electroweak and flavor precision tests. We find that the model we study is a viable model of dynamical breaking of the electroweak symmetry.
Lepton flavour nonconservation in H0 decays
1992
Abstract We calculate the off-diagonal lepton-lepton-Higgs boson vertex induced by one-loop electroweak corrections, in the context of the standard model in which one right-handed neutrino for each family has been introduced. We find that in the presence of very heavy Majorana neutrinos the lepton-flavour-violating decays of the H0 boson can be significantly enhanced yielding observable signals at high energy collider machines.
Revealing the Majorana nature of heavy neutrinos via a heavy Higgs boson
1992
Abstract Analyzing several recently proposed models, based on simple extensions of the standard model (SM), with heavy Majorana neutrinos, it is shown that the change of detecting lepton number violation through their production and subsequent decays may be significantly enhanced, if a heavy Higgs boson with mass within a reasonably broad range is present.
Search for neutral Higgs bosons from supersymmetry in Z decays
1990
The light scalar Higgs boson h and the pseudoscalar Higgs boson A of the minimal supersymmetric standard model have been searched for in the processes e+e−→hff and e+e−→hA using data collected by ALEPH at the LEP e+e− collider, with center of mass energies at and near the Z peak. Using a variety of signatures adapted to various mass ranges for h and A, we have excluded a large domain in the parameter space. For large values of ν2ν1, the ratio of the vacuum expectation values of the two Higgs fields, the whole range from 0 to 38.8 GeV is excluded for Mh and MA at 95% CL.
Lepton Flavour Violation in charged leptons within SUSY-seesaw
2009
6 pages, 6 figures.-- Pre-print archive.
Double beta decay in left-right symmetric models
1996
Left-right symmetric models provide a natural framework for neutrinoless double beta ($\znbb$) decay. In the analysis of $\znbb$ decay in left-right symmetric models, however, it is usually assumed that all neutrinos are light. On the other hand, heavy {\it right-handed} neutrinos appear quite naturally in left-right symmetric models and should therefore not be neglected. Assuming the existence of at least one right-handed heavy neutrino, absence of $\znbb$ decay of $^{76}$Ge currently provides the following limits on the mass and mixing angle of right-handed W-bosons: $m_{W_R}\ge 1.1 $ TeV and $\tan(\zeta) \le 4.7 \times 10^{-3}$ for a particular value of the effective right-handed neutrin…
Hunting a light CP- odd non-standard Higgs boson through its tauonic decay at a (Super) B factory
2007
Several scenarios beyond the minimal extension of the Standard Model still allow light non-standard Higgs bosons evading LEP bounds. We examine the mixing between a light CP-odd Higgs boson and $\eta_b$ states and its implications on a slight (but observable) lepton universality breaking in Upsilon decays which could be measured at the percent level at a (Super) B factory.